Polyethylene imine boranes and their preparation

ABSTRACT

THIS INVENTION RELATES TO POLYETHYLENE IMINE BORANES. THEY ARE PREPARED BY REACTING A POLYETHYLENE IMINE BORANES. THEY ARE PREPARED BY REACTING A POLYETHYLENEIMINE HAVING A MOLECULAR WEIGHT FROM 600 TO 100,000 WITH THF:BH3 IN TETRAHYDROFURAN. THE PRESENTLY PREFERRED BORANES ARE PREPARED AS ABOVE INDICATED USING A POLYETHYLENE IMINE HAVING A MOLECULAR WEIGHT BETWEEN 600 AND 1800. THE SOLVENT AND REACTANTS SHOULD BE AS ANHYDROUS AS POSSIBLE. THE PROPERTIES VARY WITH THE AMOUNT OF AMINO GROUPS WHICH ARE COMPLEXED TO BORANE GROUPS. THUS, THE BORANES MADE BY REACTING 1 BH3 GROUP FOR EACH 4 TO 100 AMINO GROUPS ARE VISCOUS LIQUIDS WHICH ARE FAIRLY SOLUBLE IN WATER AND ORGANIC SOLVENTS INCLUDING BENZENE. THEY ARE VERY SUBSTANTIVE TO ANIONIC SUBSTRATES AND ARE USEFUL FOR REDUCTIVE BLEACHING AND AS STABILIZING AGENTS FOR CELLULOSE, CLAY, ETC. WHEN A GREATER NUMBER OF AMINO GROUPS ARE CONVERTED TO BORANE GROUPS, SUCH AS 1 BORANE GROUP FOR EACH 2 TO 4 AMINO GROUPS OF THE POLYETHYLENE IMINE, THE PRODUCTS ARE EXTREMELY VISCOUS POLYMERS OR SOLIDS. THESE PRODUCTS ALSO RETAIN SLIGHT WATER SOLUBILITY(1 TO 5%) AND ARE USEFUL WHERE A MORE CONCENTRATED REDUCING ACTIVITY IS DESIRED.

United States Patent [72] Inventor Robert C. Wade Ipswich, Mass.

[2l] Appl. No. 834,584

[22] Filed June 4, 1969 [45] Patented Sept. 28, 1971 [7 3] Assignee Veutron Corporation Beverly, Mass.

[54] POLYETHYLENE IMINE BORANES AND THEIR Kelly et al., Journal of the American Chemical Society, Vol. 82 (1960) pages 4842 to 4846 Primary ExaminerCharles B. Parker Assistant Examiner-Richard L. Raymond Attorney]. Harold Boss ABSTRACT: This invention relates to polyethylene imine boranes. They are prepared by reacting a polyethylene imine having a molecular weight from 600 to 100.000 with TI-IF:BH in tetrahydrofuran. The presently preferred boranes are prepared as above indicated using a polyethylene imine having a molecular weight between 600 and 1800. The solvent and reactants should be as anhydrous as possible. The properties vary with the amount of amino groups which are complexed to borane groups. Thus. the boranes made by reacting 1 BH; group for each 4 to 100 amino groups are viscous liquids which are fairly soluble in water and organic solvents including benzene. Theyare very substantive to anionic substrates and are useful for reductive bleaching and as stabilizing agents for cellulose, clay. etc. When a greater number of amino groupsare converted to borane groups. such as l borane group for each 2 to 4 amino groups of the polyethylene imine, the products are extremely viscous polymers or solids. These products also retain slight water solubility (l to 5%) and are useful where a more concentrated reducing activity is desired.

POLYETIIYLENE [MINE BORANES AND THEIR PREPARATION This invention relates to polyethylene imine boranes which contain both amino groups and borane groups.

It has long been known that the amine boranes represented by the formula R NzBl-l are useful reducing agents which resist hydrolysis at pI-l 4. A wide variety of amines have been used in preparing amine boranes including polyamines, such as ethylene diamine bis borane (H BI-I NCH NI-I,BH This product, as reported by Kelly and Edwards in J. Am. Chem. Soc., 82, 4842(1960), can be prepared by the reaction of THFzBl-I and ethylene diamine in tetrahydrofuran as a solvent. This material reduces organic carbonyl compounds and metal salts, such as AgNO and Cu(NO to the pure metal. The same authors have also reported [Inorg. Chem. 2,

226(1963b] that the product has high solubility (46-47 grams per liter) in TI-IF and low solubility in water (8-9 grams per liter).

Polyethylene imines of high molecular weight, that is, having molecular weights from 600 to 100,000 are manufactured by the Dow Chemical Company under the trade name PEI. I have discovered that if only a portion of the amino groups of a high molecular weight polyethylene imine are converted to borane groups, the resulting product possesses a unique combination of properties. In the practice of the invention, I presently prefer to employ polyethylene imines having a molecular weight of 600 to 1,800.

The preparative method used in the practice of the invention is the well-known method of adding TI-IFzBI-I to a tetrahydrofuran solution of the polymer. The solvent and reactants should be anhydrous. Since the PEI" polymers contain 25 percent primary, 50 percent secondary, and 25 percent tertiary amino groups, the following locations are possible for each EH (borane) group:

Primary amine borane CH;CH NH,:BH;

In the practice of the invention, I employ a range of a number of BI'I groups from about one BH group for each 100 amino groups to about one BH group for each two available amino groups in the polymer. This range provides a unique combination of properties in the reaction product. The preferred range of number of BI-I groups is about one BH group for each four to 10 available amino groups in the polyethylene imine.

When small amounts of BII groups are reacted with the polyethylene imine, for example, one BII group for each four to 100 available amino groups the products are viscous liquids which are soluble in water and organic solvents including benzene and are very substantive to anionic substrates. These products carry'the BH reducing group to the substrate and are useful, for example, as reductive-bleaching and stabilizing agents for cellulose and clay.

When more BH groups are reacted with the polymer, for example, one BH group for each two to four available amino groups, the products are extremely viscous polymers or solids. These products also retain slight water solubility (l to 5 percent) and are useful where a more concentrated reducing activity is desired in the molecule and the reducing agent retains its stability toward hydrolysis at a pH as low as 5. These products are useful as reducing agents in chemical plating baths for nickel, copper, silver, etc. where plating is desired to take place in the pH range of five to eight.

The invention is illustrated further by the following specific examples.

The results of several run". are shown in the following table. The apparatus used was the same in each run and comprise a 500 ml. three-necked flask which was fitted with a dropping funnel, a thermometer, and a reflux condenser. A gas line connected the top of the reflux condenser with a wet test meter. The reaction flask was heated, when necessary, with a Glas- Col mantle and stirred with a mag-mix bar. The polyethylenimine (PEI) and THF were weighed into the flask before the apparatus was assembled. The products were dried H 1 by a flash evaporator except Run 6. The products all were Semndary we 41110311? dark tan to brown color after drying. 100 ml. of tetrahydrofu- 13 40 ran (THF) w a s used in all runs as solvent. I claim: 1. A polyethylene imine having a molecular weight between Tammy Emma borane CHZCHZ I.\.I CH2CH' 600 and 100,000 and having about one for each two to 100 of its available amino groups complexed to a BH group.

TABLE 1 Runs Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 t 1 PEI-6, .5 mole; PEI-6, .5 mole; PEI-18, .5 mole; PEI-18, .5 mole; PEI-6, lmole; PEI-1B, 1 mole; Actual concentm ion THFBHJ, .25 THFBI-h, .125 THFBHa, .25 THFBHJ, .125 THFBIL- .1 'IHFBII3, .1

mole. mole. mole. orroe. 10niole. 0mole. It BH 10:5 "10:25 "10:5 1: 1;1. s i g p rfiessinn Flash evap Flash evap lash evap Flash evap... Flash evap Hogsle vale. in

OI l0. Appearance dried produet Solid Semi-solid Solid Semi-solid Vilziry ligavy V(1 ry l gavy (1111 H1111 Melting point of solid in Above 60 C Above 60 C Above 60 C Above 60 Cv 42 C 45 C. li iiiiii ii ei t 2 s 1 4 2 3 1 2 0 8 Not analyzed ea ysis, percen t t Tl ieoreticahpereent 3.0 1.5 3-0 1.5 0.7 Not analyzed.

1 The molecular weight of PEI is taken as the molecular weight of one unit (CH1CH2NH) =43.

2. A polyethylene imine having a molecular weight between 600 and 1,800 and having about one for each two to of its available amino groups complexed to a BI-I group.

3. A polyethylene imine having a molecular weight between 600 and 1,800 and having about one for each four to 100 of its available amino groups complexed to EH groups. 

2. A polyethylene imine having a molecular weight between 600 and 1,800 and having about one for each two to 100 of its available amino groups complexed to a BH3 group.
 3. A polyethylene imine having a molecular weight between 600 and 1,800 and having about one for each four to 100 of its available amino groups complexed to BH3 groups. 